Newbie intro / Air Bubble and Flowering issues

[ssbogger]

glassdoctor - The tab being too stiff to flex into the pit and thus forming an air bubble seems logical but the air would still have to come from somewhere... does it get pulled in from the edges of the tab?

Screenman - I think glassdoctor was suggesting that instead of using a curing tab just drop the pit resin and then quickly start curing with the UV lamp. I have tried this method and it does work; it just leave more of a hump to scrape off and if you don't cure it fast enough the resin will run out of the pit a little and you will have to fill and cure the pit again.

[screenman]

I have cured without a tab before and suggested others try it. There is though a clue in the name of the resin you use, anaerobic ultraviolet curing.

[LWR]

I knew I wasnt the only victim! I've had the same issue with the trapped bubble in my finished repair but only on repairs that I've drilled. I make absolutely certain that I've removed all of the air from the break before I remove the bridge, place tab and cure. But too often that little bubble somehow magically appears. Most of the time it's a very small bubble and my customers are very happy with the repair. Sometimes I drill and and recure to get rid of it. I'll be trying out some of these methods mentioned. Hopefully we can find a solution!

[DryStar]

Try inverting pit fill bottle prior to use. I actually store them that way in tool box to insure no air is ever trapped prior to using them. For an example, take your syrup bottle when used. You'll see all the trapped air slowly moving up. Same with pit resin, unless you wait for air to slowly rise...it will be mixed. HTH

[pommy]

Try inverting pit fill bottle prior to use. I actually store them that way in tool box to insure no air is ever trapped prior to using them. For an example, take your syrup bottle when used. You'll see all the trapped air slowly moving up. Same with pit resin, unless you wait for air to slowly rise...it will be mixed. HTH

The air appears after the tab is applied, not before mate

I tried on my practice glass last night - it is pretty much a 5 year old resin screen now!

Anyway, I couldn't get a bubble with or without a tab/tape. These breaks were fresh though, maybe that has a bearing on it?

Back to the repair I did yesterday - well, it was a simple enough repair, minimal drilling. I placed a bubble free drop at the bottom of the hole - held the bottle there and waited for it to creep into the base, covering the bottom - then slowly filling.

Essentially the pit is filled before the tab arrives (no bubbles). I then take a tab and move the drop over the hole and place it.

I can see perfectly clear, no bubbles, no dip in the tab either - there's enough resin to avoid that.

The lamp goes on, I clean my injector - look up an there it was, a perfect repair with a bleedin' bubble!

The air cannot get under the tab. The air wasn't in the pit filler. The pit was dabbed free of Magnibond. Using a tab can't introduce air.

So by process of elimination - the air was already present in the break before the pit filler went in.

I'm thinking a different type of pit filler, thinner?

More vacuum cycles? Anyone?

Cheers,

Pommy

[DryStar]

Whatever you say Pommy....I just don't experience these problems...I guess that is what separates us.

[pommy]

What's with the attitude?

It's not my topic and not just me having this problem. Did you read or just jump in?

I was letting you know it was after the pit fill as your post didn't make sense with the running of the thread.

[glassdoctor]

glassdoctor - The tab being too stiff to flex into the pit and thus forming an air bubble seems logical but the air would still have to come from somewhere... does it get pulled in from the edges of the tab?

Screenman - I think glassdoctor was suggesting that instead of using a curing tab just drop the pit resin and then quickly start curing with the UV lamp. I have tried this method and it does work; it just leave more of a hump to scrape off and if you don't cure it fast enough the resin will run out of the pit a little and you will have to fill and cure the pit again.

Not sure if the heat thing was for me... I mentioned nothing about using heat for anything?

Anyway, about the magic bubbles. "the air would still have to come from somewhere" imo, yes and no. When the resin shrinks in a sealed space it has to either pull in air to replace the lost volume, or create a vacuum. It's likely that the air bubble is the expansion of whatever gas or air that is present in the resin, even though it's not visible to the eye prior to being cured. That may be the source of the "air". The other possibility is that the bubble is actually not gas or "air" but is a vacuum, a void. Doesn't matter which way though. I could be completely wrong on this whole thing, but I don't think so. Try this and get back to me.... drill a dozen holes of any shape and size and fill them with resin, making sure none have any bubbles prior to curing of course, and cure 6 with a tab and 6 with no tab and see what you get.

[glassdoctor]

never mind

[pommy]

never mind

Ha ha ha ha!

So funny!!